الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Coronoradicular restorations are of extreme importance in daily clinical situations due to the high incidence of tooth fractures after endodontic treatments rendering the remaining amount of tooth structure incapable of supporting or retaining a conventional coronal core.
With the evident breakthrough of various esthetic dental materials such as zirconia making coronoradicular restorations have the ability to combine between the functional and esthetic demands. This study evaluated the bond strength between the surfaces of zirconia posts and the luting resin cement after three different surface treatments.
This in vitro study constituted three groups each of ten specimens (n=10) divided according to the method of surface treatment carried out on the post surface; group (I): tribochemical silica coating, group (II): CO2 laser and group (III): Er.Cr:YSGG laser
Thirty maxillary central incisors were collected, endodontically treated and drilled with same drills to ensure standardization of the post space preparation. One glass fiber post was scanned using and extraoral scanner and thirty zirconia posts were milled having the same design and dimensions of the scanned post. The posts were then bonded to the roots and placed inside an acrylic block made from a custom made copper mould to standardize the specimen dimensions.
The bond strength was evaluated by push-out bond strength test where every specimen had three readings at the coronal, middle and apical segments after sectioning using a high precision sawing machine. The mode of failure was further evaluated using a light steromicroscope.
The mean value of bond strength within each group showed that the tribochemical silica coating group had the highest bond strength values (12.20±0.90 MPa) and (10.20±0.74 MPa) for CO2 Er.Cr:YSGG was (6.22±1.17 MPa). The data were statistically analyzed using One Way ANOVA.
One way ANOVA test was conducted and showed a statistically significant difference in the debonding load (Mpa) among the three studied groups.
In conclusion, TSC showed to have the best durable bond with resin cements moreover, CO2 showed acceptable results when compared to Er.Cr:YSGG